The Department of Justice objected to Texas’ voter ID law Monday, determining the law would discriminate against minority voters, particularly Hispanics.

“Even using the data most favorable to the state, Hispanics disproportionately lack either a driver’s license or a personal identification card,” Assistant Attorney General Thomas Perez said in a letter to the Texas director of elections.

The same day, the Brennan Center and other legal groups moved to intervene to stop the restrictive photo ID law, which will also be reviewed in federal court. The motion, on behalf of the Texas NAACP and the Mexican American Legislative Caucus, argues the law erects unnecessary barriers to voting and disenfranchises hundreds of thousands of minority voters.

“Decades ago, our nation passed the Voting Rights Act to combat this kind of discrimination,” said Brennan Center Senior Counsel Myrna Pérez. “We urge the federal court to stand up for voters by blocking this law.”

This news comes just days after a Houston Chronicle analysis found that Texas’ voter ID law “could affect as many as 2.3 million registered voters.”

As November approaches, voter intimidation looms as a next battleground. A federal court in Philadelphia last week made clear the limits to what is allowed.

The judge upheld a long-standing consent decree prohibiting the Republican National Committee from using improper election tactics. The consent decree specifically bars the organization from using voter challengers, poll watchers, and a practice known as “vote caging” to target and intimidate voters of color.

The court’s opinion described how poll watchers and poll challengers have the potential to disenfranchise lawful voters by causing delays, crowding, and confusion inside the polling place and creating a charged partisan atmosphere that can intimidate many new voters. Here’s an analysis of these past problems.

With the 2012 election fast approaching, it is important for state officials to ensure other political groups — not just the RNC — follow the law and refrain from using poll watchers to intimidate or discriminate against voters, writes the Brennan Center’s Nic Riley.